Rarity

Rarity is a term used to describe how difficult it is to obtain a particular card from an expansion in the Trading Card Game. The rarity is represented by a symbol (, , or ) on the bottom right corner of every card. Though rarity typically correlates to the actual frequency at which a card is found in official Booster packs (also known as the "pull ratio"), some cards can be uncharacteristically common or rare for their official rarity.

Fixed

Certain cards, such as those from certain decks (such as a Trainer Kit or some Japanese half or quarter decks) do not have a rarity listed on the bottom right corner of the card, and instead have the silhouette of the main Pokémon within the kit (such as the silhouette of Sylveon and Noivern in their respective half decks in the XY Trainer Kit — /).

Promos

Promos are promotional cards released during an event (such as TCG Championships) or in certain merchandise (such as in tins). They have a Black Star Promo symbol () instead of a rarity symbol in the bottom right corner.

Rarity levels

Common

Common cards are are marked with a circle () and usually consist of basic, unevolved Pokémon. Most English Booster packs contain four to five Common cards.

Uncommon

Uncommon cards are marked with a diamond () and can consist of both evolved and unevolved Pokémon. Most English Booster packs contain three Uncommon cards.

Holofoil Rare

A small amount of rare cards within each expansion are Holofoil. It may be pulled from an English Booster pack as the Rare card but is not guaranteed. They are rarer compared to non-holofoil rare cards.

There are many types of Holofoil, which occasionally changes after a series of expansions:

Between Base Set and Call of Legends (spanning every expansion from Generation I to IV), the holofoil pattern is named cosmos holofoil, and consists of dots and circles of different sizes spread across the image of the Pokémon.

Between Black and White and Legendary Treasures (every expansion from Generation V), the holofoil pattern is named tinsel holofoil, and consists of horizontal stripes across the image. In Japanese holofoil cards of these sets, the border of the card also has a tinsel holofoil effect.

Starting from XY, the holofoil pattern changed to sheen holofoil. There are differences between the language of the card; Japanese holofoil cards refract light in a diagonal direction from bottom left to top right across the entire card; Korean holofoil cards have the same effect and direction, but only cover the image of the Pokémon; and international releases have the same effect as Japanese cards, but only cover the image, and the direction is from bottom right to top left.

Certain Theme Decks have exclusive versions of the featured card: in the Black and White era, the featured card had a Cracked Ice/Shattered effect. The same effect was used in some blisters as well.

Ultra Rare

Ultra rare (also called super rare) cards are typically marked as Rare Holofoil cards, but sometimes have unique symbols denoting their rarity. As such, they will replace the rare card in the Booster pack. As their name suggests, ultra rare cards are far more difficult to acquire than typical rare cards. Most ultra rare cards are associated with a unique mechanic, such as Pokémon-ex, Pokémon LV.X, Pokémon LEGEND, Pokémon Prime or Pokémon-EX.

Pokémon ex were introduced in EX Ruby & Sapphire. The DP Era marked the end of Pokémon ex, where they were replaced with Pokémon LV.X. the ex in Pokémon ex stands for "extra" - the extra effects and attacks that Pokémon ex have. Pokémon ex broke the previous HP limit of 120 HP, as well as having more powerful attacks. They were also immune to some effects. However, they were susceptible to a larger number of negative effects meant to counter Pokémon ex, and in many instances, had more than one weakness, or a higher retreat cost. The most outstanding difference between a Pokémon ex and a regular card is that if it is knocked out, the opponent takes two prize cards instead of one. They had a cosmos holofoil effect in the image as well as on the border of the card. They rarely appeared as Secret Cards (there are rare instances, such as Rocket's Raikou ex or Rocket's Persian ex, where they appear as Secret Cards.)

Pokémon Star were featured in EX Team Rocket Returns, and last released in POP Series 5. Reminiscent of Shining Pokémon, they are alternatively colored, have beneficial attacks and the 1-per-deck rule, but no longer feature multiple Energy-type attacks (aside from Latias, Latios and Rayquaza). They have portions of their body outside the borders of the image, Golden tinges and holographic shadows are added to various parts of the card. All Pokémon Star are Basic Pokémon regardless of their stage of evolution normally. δ Delta Species Pokémon Star are the type that their shiny coloration is the color of. Their unique rarity symbol is Shiny Rare Holo ().

Pokémon LV.X were introduced in Diamond & Pearl to replace Pokémon ex and Pokémon Star, and made their final appearance in the Arceus expansion. It has the strength, rarity, holofoil borders, protruding parts of Pokémon ex and Pokémon Star. They are treated as 'Level-Up' cards, as opposed to evolution, but has the same effects as evolution: the card cannot be played on the first turn or on the turn that its non Leveled Up card is played, and lose any Special Conditions that were affecting it before Level-Up. However, Pokémon on the bench cannot be leveled up. Pokémon LV.X can still use the attacks and Pokémon Powers of the card underneath it. They had the rarity of Rare Holo LV.X ().

Pokémon LEGEND were introduced in HeartGold & SoulSilver along with Pokémon Prime as a replacement for Pokémon LV.X. Pokémon LEGEND cards have two halves - one of the top half, the other of the bottom half - and comprises of 1 or 2 Pokémon. Both cards must be played at the same time onto the bench, and is treated as one card. However, it is treated as two separate cards outside of play, for example, in the hand or deck. The illustration takes up three-quarters of the card, with the text on a corner of the bottom half. The two Pokémon are either part of a Legendary duo or trio. The entire card is holofoil, and the rarity symbol is Rare Holofoil LEGEND (). The last Pokémon LEGEND card was featured in Triumphant.

Pokémon Prime were introduced along with Pokémon LEGEND in HeartGold & SoulSilver and was last released in Triumphant. They are unique compared to other Ultra Rare cards as their names are regular and have no special game mechanics compared to normal cards. However, they are considerably stronger compared to their regular counterparts, have a different card design (with 'leering' eyes and a special design at the edge of the image border), as well a holographic image and name to reflect their rarity. Their rarity symbol is Super Rare Holo ().

Pokémon-EX were introduced in Next Destinies, and has an "EX" in its name. They are all Basic Pokémon, and were all Legendary Pokémon until the release of Legendary Treasures, which saw the first non-Legendary Pokémon-EX cards. Most, but not all, of the cards have a Full Art print as well, where the image covers the whole card. Pokémon-EX have the same rules as Pokémon-ex; they have higher HP than normal cards, and if it is Knocked Out, the opponent takes two Prize cards instead of one. Similar to Pokémon LV.X, the Pokémon 'break' the borders of the image, seeming to 'come' out of the image. An additional special effect is included on the border of each card, based on the characteristic of the card, such as leaves on the border of Shaymin-EX's card. M Pokémon-EX were introduced in XY to reflect the introduction of Mega Pokémon in the games. They had a stylized M before its name, higher HP (breaking the previous HP limit) and more powerful attacks. In terms of design, they were similar to regular Pokémon-EX, but has the name of its attack in the artwork in another language (for example, the English name of the attack on Japanese or Korean cards, and the Japanese name on international releases). In gameplay, they had to be evolved from the previous Pokémon-EX, and doing so ends the player's turn.

Secret Rare

Secret rare cards are cards with set numbers outside the printed size of the set (for example, a card numbered 101/100). These cards are generally considered a subset of ultra rares. Most secret rare cards are reprints of other cards, often from the same set, but with a unique artwork scheme such as an alternate holofoil scheme, depiction of shiny Pokémon, or a gold trim. Shining Pokémon and Crystal Pokémon are both examples of secret rares.
Previously, there were sparse amounts of Secret Rare cards released through various means, in which many were included as boxtoppers. Before the BW era, Secret cards mostly appeared in English versions, as they were either within normal set numbering or as promo cards in Japanese.
After the release of Black & White, certain types of cards were released as Secret cards; they are explained below.

Box Toppers are Holofoil cards included within a booster box as a reward for buying the whole box. Although they were Secret cards, they had regular holofoil artwork and had a regular rarity of Holofoil Rare ().

Shining Pokémon had the shiny colorations that appeared in the Pokémon games, as well as the odds of encountering one (1/300, similar to in the games). Not only are they outside the set (having a number above the number of cards in the set), they were also the first to have the rarity Shining Holofoil () to imitate the shiny sprite from the games (). Shining Pokémon could use multiple Energy-type attacks, but there could only be one Shining Pokémon per deck. Shining Gyarados (Neo Revelation 65) and Shining Magikarp (Neo Revelation 66) were the two first featured, perhaps due to their appearance in the anime and games, and were cosmos holofoils. The second and last set to feature Shining Pokémon was Neo Destiny, but the Pokémon itself (not the whole image) were given reflective foil treatment (to make the Pokémon really seem to 'shine'). The were also given the Shining Holofoil Rarity

The concept of Shining Pokémon was carried over to Crystal Pokémon, which were released in Aquapolis. Crystal Pokémon were all Colorless in type, regardless of their normal type; they had the cosmos holofoil treatment, were Secret Rares (outside the set) as well as having the multi Energy-type attacks, but were not actually alternatively colored as in Shining Pokémon. All Crystal Pokémon have the Crystal Type Poké-Body, which changes the Pokémon's type to the type of the Energy that is placed onto it if it is one of the three Energy-types that the Pokémon requires in its attacks. Crystal Pokémon appeared in Skyridge, but did not appear in the future. They have a rarity of Holo Rare in English () and Super Rare in Japanese ().

In the BW era, the first Secret cards to appear were popular Pokémon not native to Unova, as only Unova Pokémon were released in the first three sets. Two of these cards were released - Pikachu and Meowth. The Pokémon image was holofoil, and there was a holofoil design under the main text of the Pokémon's type.

In Next Destinies, Shiny Pokémon were released as Secret cards, as Pokémon not native to Unova were included into the expansions. They had the same designs (holofoil image, holofoil energy type under main text) as the previous Secret cards.

In Dark Explorers, certain item cards were given Secret card prints as well. Various parts of the card (such as the border, or the text box of the name of the card) were golden; the image was holofoil, and there was a Poké Ball design printed under the main text. Some were even given redesigns - an example would be the Random Receiver, which was golden instead of black.

Legendary Treasures featured two special Secret cards: Reshiram and Zekrom were given an additional Full Art print, in which the whole card was golden.

With the release of Flashfire and Mega Pokémon-EX, prints of M Pokémon-EX cards with golden borders were released as Secret cards.

Full Art prints of Pokémon were introduced in Black & White; Full Art prints of Pokémon-EX were introduced in Next Destinies; and Full Art prints of Supporters were introduced in Noble Victories. Although there were within the set for English releases (and therefore not Secret cards, they were Secret cards in Japanese releases.